Clamp power supplies are used as part of an ongoing push to make power supplies smaller and more efficient. An example clamp power supply includes a clamp circuit in parallel with the input of a switching regulator. Under steady state load conditions, the clamp circuit does nothing, i.e., it appears as high impedance. If an abrupt load change occurs which is sufficient to cause the output voltage of the switching regulator to exceed a certain tolerance band, the clamp circuit will turn on and shunt additional charging current to ground. Accordingly, when the output of the voltage switching regulator drops below a threshold, the clamp turns off. The output voltage of the switching regulator begins to recover as the input charges. A similar function is needed when the load changes from high to low. Since the inductor current cannot decrease instantaneously, the output voltage will increase, at which point clamp circuit would turn on and sink current.